The goal of this Program Project is to demonstrate that radiolabeled, engineered antibodies can be used to treat human colonic cancer. The responsibility of Core 9003, Large-Scale Culture and Purification of Antibody, is to produce engineered antibody of sufficient quantity and purity for the human imaging and Phase I/II therapy studies that are focus of the program, and for the research studies in Projects 1 and 6. It is estimated that the initial Phase I trial will require production and purification of 2.4-3.0 grams of cT84.66. The Core will assist Project 2 (Engineered Antibodies) in the identification of high-producing cell lines for each of the engineered antibodies. These cell lines will be tested in accordance with the FDA "Points to Consider in the Characterization of Cell Lines Used to Produce Biologicals, (1987)", and "Points to Consider in the Manufacture and Testing of Monoclonal Antibody Products for Human Use, (1987)". Antibody will be produced in a state- of-the-art hollow-fiber bioreactor which is capable of producing gram quantities of antibody, which is both concentrated and reasonably pure as it is harvested. The antibody will be purified by Protein G affinity and anion exchange chromatography. The purified antibody will meet the specifications set forth in the FDA "Points to Consider in the Manufacture and Testing of Monoclonal Antibody Products for Human Use, (1987)". Specific attention will be given to requirements that the purified antibody pass an appropriate pyrogen test and that it contain < 10 pg DNA per injectable dose. Purified antibody will be transferred to Core 9001 (Radiopharmacy) where it will be conjugated with an appropriate chelator and radiolabeled for subsequent human trials.